The demands upon an automotive vehicle concerning the emissions in the exhaust gases are very rigid, and may be expected to be still further increased. A further demand, which also will be raised, concerns curves, increased safety with respect to maneuverability, capacity for taking curvs, acceleration and retardation on slippery roads, as well as with respect to injuries to passengers and damages to material caused by collisions. The latter consideration will necessitate more efficient bumpers, requiring increased length and cost of he car, or a reduction of the space available for passengers and luggage. Neither is acceptable to any larger extent.